Luminescent and morphological study of Sr2CeO4 blue phosphor prepared from oxalate precursors

Luminescent and morphological studies of Sr2CeO4 blue phosphor prepared from cerium-doped strontium oxalate precursor are reported. Powder samples were prepared from 5 and 25 mol% Ce3+-doped strontium oxalate as well as from a mechanical mixture of strontium oxalate and cerium oxalate at a 4:1 ratio, respectively. All the samples were characterized by XRD, IR, PLS, and SEM. The luminescent and structural properties of the Sr2CeO4 material are little affected by the SrCO3 remaining from precursors. The Sr2CeO4 material consists in one-dimensional chains of edge-sharing CeO6 octahedra that are linked together by Sr2+ ions. The carbonate ion might be associated with oxygen ions of the linear chain, and also with the oxygen atoms located in the equatorial position, which consequently affects the charge transfer bands between O2− and Ce4+. As observed by SEM, the morphological changes are related to each kind of precursor and thermal treatment, along with irregular powder particles within the size range 0.5-2 μm.